As exemplified by teachings of U.S. Pat. No. 1,614,471 (Hayashi--Jan. 13, 1927); U.S. Pat. No. 2,859,968 (Modica--Nov. 11, 1958); and U.S. Pat. No. 3,159,273 (Viby--Jul. 7, 1970): the prior art teaches some unpredictably tumbleable capsule structures intended to raceably compete with identical capsule structures along a selectable downwardly-inclined ramp means. However, such prior art capsule structures are structurally deficient in that they do not provide, even among several identically structurally constructed capsules, non-predictive competitive racing success along the same downwardly-inclined ramp means.